L134 Lubrication System Simply Explained by TONY NORTON

1941 - 1945, MB, GPW Technical questions and discussions, regarding anything related to the WWII jeep.
User avatar
artificer
banned
Posts: 13558
Joined: Tue Jul 11, 2006 10:46 am
Location: SINGAPORE

L134 Lubrication System Simply Explained by TONY NORTON

Post by artificer » Mon Feb 19, 2018 12:25 pm

TONY NORTON wrote:
All You Wanted to Know About Go-Devil L-134 Lubrication System But were Afraid to Ask.

Okay….First, let’s play the WWII jeep oil pressure game. It’s easy. Everyone open their mouth wide, and take a deep breath. With your mouth still open wide exhale forcefully. Do this a couple of times. Now, take a deep breath, but this time purse your lips and exhale forcefully. Did you notice that when you did this your cheeks puffed out? Now, remember this and continue reading.

Now let’s review the L-134 lubrication system. But before we do let’s define Pressure as “The action of a force against some obstacle or opposing force; a force in the nature of a thrust, distributed over a surface, often estimated with reference to a unit's area. “ and Flow as “The amount of fluid that flows in a given time”.

Oil Pump
Let’s start with the oil pump. Let’s clear up one sticky point before we go any further. The oil pump does not generate any “pressure” whatsoever. It only creates “flow.” “Restrictions” to flow create pressure.

The oil pump in the Go-Devil engine has a flow rate of one gallon per minute at 250 oil pump (OP) RPMs. The oil pump RPM is 1/2 engine RPM. So, if the engine is idling at 500 RPM, the OP RPM would be 250.

Now, if the engine RPM is raised to say… 2000 RPM, the OP RPM would be 1000, and the flow rate would be 8 gallons per minute.

Oil Galleries
Now let’s go back a look at the idle speed. At 250 OP RPM, pushing one gallon of oil a minute through an approximately 3/8” diameter main oil gallery with the plugs removed would be easy. So the oil flows unrestricted, so you have flow with no restriction, so no pressure. As the engine RPM is increased, in turn increasing the OP RPM and flow rate, the oil pump is trying to push a higher volume of oil through that 3/8” diameter oil gallery. Given the increased flow rate, the friction of the oil against the sides of the oil gallery will create a slight “restriction” to the flow of the oil and will create a little pressure.

Oil Pressure Gauge
Now, let’s plug all the openings to the main oil gallery and attach an oil pressure gauge into the main oil gallery on the left rear side of the engine. If we now turn the engine, and drive the oil pump, oil will fill the gauge line compressing some air into the line. Because air is more compressible than oil, slightly lower gauge readings will result than if this line were filled with oil and then attached to the gauge.

Oil will also now fill all the secondary oil galleries that supply oil to the cam shaft and crank shaft bearings. At this point we now have oil filling what we call a “Constant Volume.” This Constant Volume is made up of the main and secondary oil galleries, and the oil pressure gauge and line.

With the constant volume full of oil, the engine operating at 500 RPM, the OP RPM at 250 generating a flow rate of one gallon per minute being restricted by the oil gallery plugs and oil pressure gauge, the gauge will indicate the resultant restriction as “pressure”.

Crankshaft and Cam Bearings
Now we are taking the oil that was flowing through the 3/8” diameter main oil gallery and causing it to flow through several smaller galleries, and then around the crankshaft and camshaft journals. The clearance between the journals and the bearings can be considered as relief ports to the restriction built up in the constant volume of the oil galleries. As the bearings wear and the bearing clearances widen, it effectively makes the relief ports larger. Therefore, more oil can flow unrestricted through the oil galleries and around the journals. This has the effect of increasing the flow rate and reducing the pressure, which is reflected by the indication on the oil pressure gauge.

Oil Pump Relief Valve
We have been talking about flow rate, restrictions, and constant volume. Let’s remember that a resistance or restriction to flow can be measured as pressure. There is a relief valve in the oil pump body that is calibrated in PSI (pressure). It is a spring-loaded poppet valve that is forced off its seat at 50 PSI and is fully open at 75 PSI.

With the engine at idle (500 RPM) and the oil pump is running at 250 OP RPM the relief valve is closed, and at full pump flow rate should be generating 25 PSI at the output of the pump. Given that some of the oil is “flowing” past crankshaft and camshaft journals, the additional oil is not being forced into the constant volume of the oil galleries and oil gauge, so the gauge will indicate a pressure equal to the output of the pump (25 PSI.)

Now, as the engine RPM increases, the OP RPM will also increase as well as the flow rate. As the flow rate increases and more oil is being forced into the constant volume two things happen. (1.) The oil pressure gauge will indicate the increasing system pressure caused by the restriction to flow of the oil, and (2.) as the flow rate increases the restriction to flow will cause the relief valve to begin to open and shunt the excess oil that cannot be forced through the system directly back in to the oil sump. Since the working range of the relief valve is 25 to 75 PSI, on an unworn engine you should see a minimum oil pressure of 25 PSI at 500 RPM and a maximum oil pressure of 75 PSI at higher RPM. Added is the oil pump relief valve set properly will reduce tis to around 55psi unless the oil is very cold. As the bearings in the engine wear, there is less restriction in the oil flow path, so even if the pump is putting out the full flow rate, the indicated pressure will be lower, based on how much the restriction has been reduced at the bearing clearances.

Oil Filter
The oil filter used on the Go-Devil L-134 engine is a “bypass” type oil filter. What this means is that not all the oil in passed through the filter 100% of the time. A “full flow” oil filter inlet is connected directly to the outlet of the oil pump. The outlet of the full flow filter is connected to the engine main oil gallery. In the bypass filter, the inlet of the filter is tapped into the main oil gallery.

In this lubrication system the oil enters the filter canister at the side at the top, fills, flows through the filter element, and then flows out through a small hole in the standpipe in the center of the filter. The outlet of the filter is connected to the engine timing cover, where the oil returning to the sump is used to lubricate the engine timing chain and gears.

There is some controversy that a bypass type oil filter is not as effective as a full flow filter. Remember that the oil pump is pumping 1 gallon a minute a 500 RPM and 8 gallons a minute at 2000 RPM. Since the filter is pulling the oil flow off the main oil gallery it is taking advantage of the full flow rate of the oil pump. So if your engine is operating at a constant 1500 RPM all the oil is being passed through the filter about two and half times in one minute.

Bypassing the Bypass Filter
There was statement in one of the popular jeep restoration books that advised to bypass the inefficient bypass oil filter. If you got anything out of the paragraphs above describing this oil filter you should now realize that it is very efficient, and the information presented in the book is WRONG.

However, let’s say you are not convinced. So what happens when you bypass the filter. There are two ways you might do this.

(1.) You could plug the oil gallery outlet tap just in front of the fuel pump and just stop the flow of oil to the filter. This method will result in depriving the engine timing chain and gears of all lubrication. That front crankshaft counterweight may be “going like a devil”, but it is not doing a cannonball, and the oil just does not splash that high. Oil pressure as seen at the oil pressure gauge will remain unaffected.

(2.) You could remove the oil line from the input to the oil filter canister and connect it directly to the port on the timing cover. Seems effective right? Timing chain and gear get lubed. Well…yes they do. But let’s look at what you’re missing.

First, you have no oil filtration at all. So hard little carbon deposits from the combustion process, plus tiny bits of abraded metal don’t get filtered out of the oil. These little guys get forced back into that tiny space between the crankshaft and camshaft bearings. This debris acts just like grinding medium and grinds away at both the bearings and the crankshaft and camshaft journals.

Second, the oil flow is going to take the path of least resistance, or should I say “restriction.” This would be the path provided by that flex oil line you connected to the timing cover. It’s as big as the main oil gallery. So guess where most of the oil is going to go? And since the flow is not as restricted as when going through the oil filter, the pressure you see on the oil pressure gauge will be less with the filter out of the circuit than with the filter in the circuit. As the engine bearings are quickly eroded away, you may think the timing chain and gears are thanking you, but they are being eaten up by the same debris that is circulating in the unfiltered oil.

Engineering the Bypass Oil Filter
Many folks have looked at the oil filter canister and wondered “How does this thing work?” You can see where the oil goes in. You can see where is comes out. You see the pipe in the middle that is plugged by the cover bolt, so how does the oil get into that pipe if the bolt is plugging it. Well, about an inch down the standpipe is a small hole that the oil passes through to the outlet fitting at the bottom of the canister. From here the oil flows through a flex line attached to the timing cover and flows onto the timing chain and gears.

Why didn’t they just make a screw on top to the oil filter and let the oil just run out the bottom you ask. Why didn’t they make that tiny hole bigger so more oil can get through it. Here’s why. That tiny hole in the standpipe that the oil must flow through to exit the oil filter is an “engineered” metering hole. The size is calculated based on the total bearing clearance of new bearings. This equals a hole about .055" in diameter.

The reason for this is if the hole was not there, or was any bigger, the oil flow would take the path of least resistance (here we go again, restriction). So, most of the oil would flow forward through the oil gallery, the flex line, into the oil canister, and back to the sump through this hole rather than flowing to the crankshaft and camshaft bearings. This would deprive these bearings of vital flow of oil they would need at the most critical time, which is the bearings half-life.

The hole is the same size as the combined new bearing clearances (about .055"), so oil flows through the main oil gallery, splits off and an equal amount is sent to the bearings and oil filter. As the bearings wear, there is less restriction, so more oil flows to the bearings, but the flow going to the oil filter remains constant because the metering hole never changes size.

How Do I Increase Low Oil Pressure (On the Gauge)?
There is talk about shimming the relief valve spring in the oil pump to increase the output pressure. What this does is to cause the relief valve operating range to move higher. Shims are install in a new pump. Each shim accounts for approximately 5 PSI in the pressure to unseat the relief valve. Shimming this spring is actually used in the manufacture of the pump to set the opening threshold of 25 PSI required to unseat the relief valve. Adjusting the output pressure by adding or removing shims is done at the final assembly pressure test to compensate for variances in the tolerances of the final machining of the pump rotors and body casing.

The end user may elect to attempt to raise the pumps output pressure by adding shims. However, if the pump is badly worn adding shims will not improve the pressure. In 98% of cases shimming the oil pump will not cause the oil pressure to increase because the bearing are worn to the point that there will still be “unrestricted flow” through the wide bearing clearances. Minimum specification oil pressure on the gauge is 10 PSI. Any less than this means that the engine requires that the crankshaft and cam bearings be replaced. And, if you are replacing these bearings you might as well overhaul the engine .


So I Rebuilt My Engine. Why is the Oil Pressure Still Low?
This is a situation that plagues a lot of restorers who hope to get that little Go-Devil humming by doing a rebuild. You started out with real low oil pressure, rebuilt the engine, put in new properly sized crankshaft bearings and a new cam bearing. You did everything right. The oil pressure did go up some, but not as much as you thought it would. And you still don’t have that 25 PSI at idle.

Let’s talk about that cam bearing. There is only one, but there are four cam bearing surfaces. The bearing is located in the front because that is where most of the bearing load stress is concentrated. No one expected these engines to go this long, and not have a readily available replacement block waiting in a warehouse to be picked and sent to you for a small pittance.

So, given the years that these engines have been in service, it would be reasonable for one to expect that if the lone cam bearing wears what about the other three bearing surfaces? The cam bearing clearance tolerances is .002” to .0035”. Note that the high limit is a bit loose as compared to the main bearings at .001” and the rod bearings at .0008 to .0023”. So, the original engine designers thought that when the other three cam bearing surfaces wore to the point that there was more than .0035” clearance, the block would be replaced.

Well…we can’t readily do that….can we? So here’s what happens. You rebuild the engine, hone the three cam bearing surfaces (open them up a smidgen more), and maybe replace the camshaft. Remember that restriction thing we talked about earlier? Now that those three cam bearing surfaces are a little wider, there is less restriction in this area, so the oil flow rate pass these cam journals is increased, so the developed pressure “at these points” in the engine is less. Take this reduction of the total restriction to the flow of oil in the lubrication system, and you see that the resultant pressure cannot be as great as if the restriction in these bearing surfaces was within the clearance specification.

So, what do I do now? Okay…your cam bearing surfaces are shot. You can’t find a replacement block. You found a replacement block but you can’t afford it now.

Hmmm….woe is me. But wait…your friendly neighborhood auto parts store and machinist to the rescue. Go to the auto parts store and buy a cam bearing kit for a Ford 302 cubic inch V-8. It will have four cam bearings. Take these to your friendly neighborhood machinist and have him bore the block to accept these cam bearings in the block webbing. Install them and then ream them to the specification clearance for each cam journal.

Shhhh….if you don’t tell that jeep judge, I won’t. And I don’t think the judge will tear your engine down to see why the oil pressure is so good. And guess what? Now you’ll be doing the Great Oil Pressure Happy Dance.
John GIBBINS Member Institute of Automotive Mechanical Engineers [Ret], ASE Master Medium/Heavy Truck & Auto Technician USA -2002 Licensed Motor Mech NSW MVIC 49593 Current 2015
TO DIAGNOSE, TROUBLESHOOT OR FAULT FIND ANY AUTO SYSTEM....
Understand how system parts interact with one another. GOOD parts can then be established & the NOT GOOD problem/s part/s isolated for repair or replacement.


rjbeamer
G-Colonel
G-Colonel
Posts: 1406
Joined: Mon Jul 06, 2009 4:55 pm
Location: Oakdale Ca

Re: L134 Lubrication System Simply Explained by TONY NORTON

Post by rjbeamer » Mon Feb 19, 2018 3:17 pm

Good reference John. Mr Norton Obviously understands and is educated in Hyd. Pump Dynamics.

But you are wasting your time with this Luc guy and his uneducated opinion.
If you notice in the past on this subject he always gives his OPINION only and never cites any professional Journals or text books on the subject. And then berates you when you do list or cite a professional reference.

Roger

User avatar
artificer
banned
Posts: 13558
Joined: Tue Jul 11, 2006 10:46 am
Location: SINGAPORE

Re: L134 Lubrication System Simply Explained by TONY NORTON

Post by artificer » Mon Feb 19, 2018 4:56 pm

Tony's article stands by itself as authoritative. There is no need to try & pull it apart or nit pick.
It is well thought through & meant to help DIY'ers understand a very simple Jeep engine positive displacement pump lube system. The job the pump does moving a constant amount of oil for each revolution as Tony enunciated.
The article was thought valuable enough to re-post. Should be a sticky!

Folk like Tony NORTON, Pete SILFVEN, Al BRASS, Derek EDDLESTONE etc. used to really contribute valuable stuff on G503, only to be run off by a certain argumentative baiter person, rather than wasting their time.
Nothing of value has been added to this thread [in red], just the usual tripe from someone self taught.

For those wanting to learn Tony NORTON [as did Pete SILFVEN & Al BRASS] made many great informative contributions/posts, so it may be worth their time searching. Unfortunately many pictures went by the way when photobucket screwed stuff up.
Last edited by artificer on Mon Feb 19, 2018 6:49 pm, edited 1 time in total.
John GIBBINS Member Institute of Automotive Mechanical Engineers [Ret], ASE Master Medium/Heavy Truck & Auto Technician USA -2002 Licensed Motor Mech NSW MVIC 49593 Current 2015
TO DIAGNOSE, TROUBLESHOOT OR FAULT FIND ANY AUTO SYSTEM....
Understand how system parts interact with one another. GOOD parts can then be established & the NOT GOOD problem/s part/s isolated for repair or replacement.

Bart1015
G-Major
G-Major
Posts: 913
Joined: Wed Apr 16, 2014 6:20 pm
Location:
Contact:

Re: L134 Lubrication System Simply Explained by TONY NORTON

Post by Bart1015 » Mon Feb 19, 2018 5:02 pm

I think the write up was very well done. Rjbeamer gave a great overview and it was well thought out.

I did not see anything incorrect or misleading.

To me it appears Bantamj just wanted to belittle the writeup. I understand the oil pump may be apart of the low pressure issue, but this was not about a bad oil pump. It was an overview on the oil flow and pressure related to flow.

If the writer addressed the pump, then he would have also had to address clogged oil passages ect. Thats probably why he did not dive into the reason why the hole in the filter tube is not at the bottom. It just did not apply, the hole size did apply to the write up.

This is a classic case of "no good deed will go unpunished".

RJBeamer, thank you for taking the time to writ this up.

Brett
1942 VEP GPW, J-2 winch, BC-659, 1919a4
1945 GPW, 1943 MBT
Sold - 1967 M151a1, 1943 MB, M416
www.ToThePointPolygraph.com

dinof
G-Major General
G-Major General
Posts: 2860
Joined: Fri Jan 08, 2010 4:32 pm
Location: Arcadia & Johannesburg Ca.

Re: L134 Lubrication System Simply Explained by TONY NORTON

Post by dinof » Mon Feb 19, 2018 7:13 pm

I get what Tony was saying, but I still don't understand (and it's really never explained here much) what oil pressure readings should be at when you have driven the jeep a good distance. In the summer, driven a good distance I can get only around 15-18 psi at idle, but it will also shoot up to 50-55psi the minute you start driving. So, what is to be expected when the engine is hot & driven in the heat??? I'm using 30wt oil.

Tony's explanation says it should be 25psi at idle. Is this with a cold engine or what?

Thanks in advance,
Dino
Dino Falabrino
On the "G" since 1998.
1943 GPW 102310 DOD 3-3-43
1928 Model A Roadster Pickup
1930 Model A Tudor
1968 Taco Minibike

User avatar
artificer
banned
Posts: 13558
Joined: Tue Jul 11, 2006 10:46 am
Location: SINGAPORE

Re: L134 Lubrication System Simply Explained by TONY NORTON

Post by artificer » Mon Feb 19, 2018 7:29 pm

Rarely is L134 oil pressure ever 25# @ idle, even when the engine & oil is cold.
It shoots up because the pump is a positive displacement type & as Tony correctly says you must get higher flow with RPM increasing.
This causes pressure to increase as the restrictions are the same except for:
The pressure relief valve [PRV] now opens & closes to maintain a constant....Tony's says 55# by dumping excess oil flow back to sump.
The PRV is a variable hole size [leak] that becomes exposed @ pressure varying in size, unlike fixed leaks such as bearing clearances.
I recommend setting & expecting oil pressure to be constantly @ 45# when hot & running @ RPM.
John GIBBINS Member Institute of Automotive Mechanical Engineers [Ret], ASE Master Medium/Heavy Truck & Auto Technician USA -2002 Licensed Motor Mech NSW MVIC 49593 Current 2015
TO DIAGNOSE, TROUBLESHOOT OR FAULT FIND ANY AUTO SYSTEM....
Understand how system parts interact with one another. GOOD parts can then be established & the NOT GOOD problem/s part/s isolated for repair or replacement.

User avatar
Chuck Lutz
Gee Addict
Posts: 26829
Joined: Wed Jun 28, 2006 7:00 am
Location: Jeep Heaven

Re: L134 Lubrication System Simply Explained by TONY NORTON

Post by Chuck Lutz » Tue Feb 20, 2018 6:20 am

FLOW...creates...PRESSURE, without flow there is no pressure and when there is flow, there is pressure. Trying to separate them is not possible. Restricting flow raises pressure, they go hand in hand.

Raise the flow and the pressure rises. Lower it and the pressure is lowered.
Raise the restrictions in the system and the pressure rises, Lower it and the pressure is lowered.
Chuck Lutz

GPW 17963 4/24/42 Chester, PA. USA 20113473 (USA est./Tom W.)
Bantam T3-C 1947

Wolfman
G-Lieutenant General
G-Lieutenant General
Posts: 6876
Joined: Sat Jan 12, 2008 5:25 am
Location: Tipton,In.

Re: L134 Lubrication System Simply Explained by TONY NORTON

Post by Wolfman » Tue Feb 20, 2018 6:34 am

I thought it was a good article. Tony rambled a little and sometimes, that looses readers, but well worth the time, so read it. ( Been known to ramble myself ! ). Good read for new people and a good refresher for us old farts.
Nice description of an L-134 lube system.
Good description of an " open center " hydraulic system -101.
Not talking NASCAR or NHRA. Just basic 70 year old jeeps. As they should be in "new " or "Rebuilt " condition.
Dino, we had this discussion a while back. About your oil pressure being up. The article addresses this.
The system Tony described uses a G-rotor pump. You said your rebuild has a newer " Melling" gear pump. The gear pump produces a higher flow rate.
Read the article. More flow out to the same oil loss, through the normal restrictions equals higher oil pressure.
Really found his note that 302 Ford V-8 cam bearings will work in an L-134 block, with a little machining, to replace worn, rear, in block cam bearings.
Gonna write that one on the wall over the tool box !!
I agree, Chuck.
Mike Wolford
CJ-2A
VEP GPW
Comm./Inst. SEL
AOPA ( 50 yrs)
EAA ( 49 yrs)
4th Inf. Div. - 5th Inf. Div. - 2nd Armor Div. - CIB

Ernie Baals
G-Lieutenant General
G-Lieutenant General
Posts: 4387
Joined: Wed Apr 23, 2003 9:27 am
Location: Southern New Jersey

Re: L134 Lubrication System Simply Explained by TONY NORTON

Post by Ernie Baals » Tue Feb 20, 2018 7:32 am

Great write up
While flow and pressure are directly in related to each other, the can be separated, like volts and amps!! Volts is the flow, amps the resistance.
When i rebuilt my GPW engine, the first time a fired it up, i had bypassed the oil filter with a line from the port on the block to the timing cover, And as Tony said, my oil pressure was low, as soon as i put the oil filter in line it show up to where it should be.
I have had many people tell me this can not happen, Well they are wrong, it did and it does
Thank you Tony!!!
Rip Dad 1/22/24 to 12/21/11
I will always love and miss you.
Ernie Baals MVPA 104C and 3104, AACA, SJC MVPA

Fathom the hypocrisy of a Government
that requires every citizen to prove
they are insured……but not everyone
must prove they are a citizen”

User avatar
Sean Collins
G-Colonel
G-Colonel
Posts: 1422
Joined: Fri Mar 19, 2004 7:40 am
Location: North Idaho
Contact:

Re: L134 Lubrication System Simply Explained by TONY NORTON

Post by Sean Collins » Tue Feb 20, 2018 8:22 am

Bart1015 wrote:
Mon Feb 19, 2018 5:02 pm
I think the write up was very well done ... I did not see anything incorrect or misleading.
Agreed, very well presented, but there is one simple error (mentioned in the past, but has not been acknowledged).

In this conclusion ...

"The hole is the same size as the combined new bearing clearances (about .055"), so oil flows through the main oil gallery, splits off and an equal amount is sent to the bearings and oil filter."

... is a simple mathematical error that even rocket scientists at NASA have made: failure to standardize units of measure.

The bearing clearances were all calculated as cross-section AREAS, but the standpipe hole is a LINEAR DIAMETER - apple and oranges, can't be directly compared.

The AREA of the standpipe hole is ~.003" - approximately equal to a SINGLE main bearing.

Ultimately, less than 10% of the oil flows thru the filter, the other 90+% goes to the bearings.
 

User avatar
Sean Collins
G-Colonel
G-Colonel
Posts: 1422
Joined: Fri Mar 19, 2004 7:40 am
Location: North Idaho
Contact:

Re: L134 Lubrication System Simply Explained by TONY NORTON

Post by Sean Collins » Tue Feb 20, 2018 8:37 am

bantamj wrote:
Tue Feb 20, 2018 8:32 am
I disagree Sean, the oil flow through the filter is much more than 10%
I know that because I tested it.
It is about 40% filter and 60% bearings & squirts on a fresh rebuild engine.
Your test setup was flawed. I said it back then and I stand by it now.
 

Ernie Baals
G-Lieutenant General
G-Lieutenant General
Posts: 4387
Joined: Wed Apr 23, 2003 9:27 am
Location: Southern New Jersey

Re: L134 Lubrication System Simply Explained by TONY NORTON

Post by Ernie Baals » Tue Feb 20, 2018 8:55 am

You could also say volume instead of flow
On older fire trucks, the pumps for the hoses used to have a control knob to choose either pressure of volume
so you can separate the two
Rip Dad 1/22/24 to 12/21/11
I will always love and miss you.
Ernie Baals MVPA 104C and 3104, AACA, SJC MVPA

Fathom the hypocrisy of a Government
that requires every citizen to prove
they are insured……but not everyone
must prove they are a citizen”

rjbeamer
G-Colonel
G-Colonel
Posts: 1406
Joined: Mon Jul 06, 2009 4:55 pm
Location: Oakdale Ca

Re: L134 Lubrication System Simply Explained by TONY NORTON

Post by rjbeamer » Tue Feb 20, 2018 9:13 am

Good day Ernie. On fire trucks that have a choice of Pressure or Volume the pumps were 2 stage pumps. In Volume position the water was run through 2 impellers in Parallel. For Pressure (or series) you could divert the water from one impeller of the pump to the intake of a second impeller through a change over valve and your final discharge pressure would be higher and at a lower engine RPM. Most fire pumps today are single stage pumps having only one impeller.

It was a common type of pump when you had a need for higher than normal pressures (Say above 200 psi) for high rise buildings or the use of high pressure hand (hard) lines.

Roger

VancleVector
G-Private
G-Private
Posts: 3
Joined: Fri Jul 27, 2018 12:47 am
Location:

Re: L134 Lubrication System Simply Explained by TONY NORTON

Post by VancleVector » Wed Aug 15, 2018 12:40 am

I really like this article. I did not know what is the specification of L134 lubrication system, but thanks tony i knew it now. :D :D :D

I have read many posts about it before and none of them are really simple. :cry:

I did not understand the flow of it and more.

SCORPIO
G-Private
G-Private
Posts: 5
Joined: Tue Sep 01, 2015 5:23 pm
Location:

Re: L134 Lubrication System Simply Explained by TONY NORTON

Post by SCORPIO » Tue Jul 04, 2023 2:15 pm

dinof wrote:
Mon Feb 19, 2018 7:13 pm
I get what Tony was saying, but I still don't understand (and it's really never explained here much) what oil pressure readings should be at when you have driven the jeep a good distance. In the summer, driven a good distance I can get only around 15-18 psi at idle, but it will also shoot up to 50-55psi the minute you start driving. So, what is to be expected when the engine is hot & driven in the heat??? I'm using 30wt oil.

Tony's explanation says it should be 25psi at idle. Is this with a cold engine or what?

Thanks in advance,
Dino
I know this is an old post, but my l134 has the exact same pressure as yours. I inherited a Jeep with 60k original miles. I use 30 w oil. Starts cold at 50+ psi warms up to 15psi at idle at 190*f. My opinion is that our engines run fine and Tony’s 25 psi is wrong.


Post Reply

Return to “MB GPW Technical Knowledge Base”

Who is online

Users browsing this forum: Bing [Bot], Google [Bot], MB210581, Sixgun, Wolfman and 77 guests